A store ordered 750 candles a total wholesale cost of \$7910.20. The soy candles cost \$12.17 each and the specialty candles cost $9.58 each. How many of each were bought?
To solve this problem, we have to model the question mathematically using simultaneous equations becasue there are two unknowns that we need to determine.
Let $x$ be the number of soy candles and $y$ be the number of speciality candles.
From the given information, we can write:
\[x+y=750\]
\[12.17x+9.58y=7910.20\]
Let us make $x$ subject of formular in the equation $x+y=750$
\[x=750-y\]
Knowing the value of $x$ in the first equation, we can now substitute in the second equation as follows:
\[12.17(750-y)+9.58y=7910.20\]
\[9127.5-12.17y+9.58y=7910.20\]
\[2.582y= 1217.3\]
therefore $y=471.46$
Knowing that $x=750-y$,we can now substitute for $y$
\[x=750-471.46 = 278.54\]
But these are candles and cannot have the fractional parts, therefore there are 471 speciality candles and 278 soy candles (after rounding down the values of $x$ and $y$).